Complete Guide to HL7 FHIR: Fast Healthcare Interoperability Resources

Complete Guide to HL7 FHIR: Fast Healthcare Interoperability Resources
With the advancing times, Healthcare records are progressively turning to digitization. Anyway, it is essential that patients electronic health records are discoverable, available, and comprehensible, whenever they move around the healthcare ecosystem. Also, the data must be structured and standardized to support the automated clinical decision and other machine-based processing.

For over 20 years now, HL7 has been addressing these challenges by producing healthcare data exchange and information modeling standards. Well, the latest standard to be developed under the HL7 organization is HL7 FHIR. We can use it as a stand-alone data exchange standard.

Also, it can and will be used in partnership with existing widely used standards. However, there is much more left to learn about FHIR. So, let’s learn about FHIR in detail. And, as HL7 created FHIR, we will begin with a brief intro to the HL7 organization.

The HL7 Organization

Well, the Standards Developing Organization accredited by the American National Standards Institute (ANSI) to write consensus-based standards representing a board view from healthcare system stakeholders is HL7.

It has compiled a collection of message formats and related clinical standards that define an ideal presentation of clinical information, and collectively, the standards provide a framework in which data may be exchanged.

Overview of FHIR

FHIR refers to Fast Healthcare Interoperability Resources. It is well known as a next-generation standards framework created by HL7. Moreover, it comprises the best features of HL7’s other standards, including v2, v3, and CDA product lines.

Also, it leverages the latest web standards and lays a strong focus on implementability. Moreover, it is considered as an interoperability standard for the electronic exchange of healthcare information.

FHIR’s design is based on RESTful web services. With this RESTful web services, basic HTTP operations are incorporated such as Create, Read, Update, and Delete. It's supported standard elements known as “resources.” Further, these resources are combined along to resolve clinical and body issues in a very sensible manner.

The resources are extended and custom-made to generate a lot of manageable solutions to the application demand for optionality and customization. Systems will scan the extensions mistreatment an equivalent framework as alternative resources.

Here are some of the key points on which FHIR standard is based:
  • Faster to learn and implement
  • Lower cost
  • Easily scale from simple to complex
  • Flexible
  • Free

What is the Aim of FHIR?

To simplify implementation without sacrificing information integrity, FHIR is used. Especially for exchanging data between healthcare applications, it holds existing logical and theoretical models to offer a consistent, easy to implement, and a rigorous mechanism.

Moreover, for traceability to the HL7 RIM and other important content models, it has built-in mechanisms. And, even without requiring the implementer to have intimate knowledge of the RIM or any HL7 v3 derivations, it ensures alignment to HL7's previously defined patterns as well as best practices.

Why is FHIR Important?

No wonder, health IT and electronic health records (EHRs) continue to be plagued by interoperability problems. So in 2014, FHIR emerged as a draft standard for trial use to enable health IT developers to more quickly and easily build applications for EHRs and to exchange and retrieve data faster from applications.

Initially, FHIR was an experimental project for HL7, but somehow, it quickly acquired support from even fiercely competitive EHR vendors including Cerner Corp., Epic Systems Corp., and AthenaHealth Inc.

The Argonaut Project, an HL7-backed association that involves the two EHR giants and different major health IT vendors, sprung up and moved FHIR toward the purpose and became a full standard, though it was still for trial use in February 2017. Also, HL7 is expected to grant FHIR full standard status soon.

Apart from this, one more significant FHIR initiative is “SMART on FHIR." It is based at Boston Children's Hospital. Also, it has gained broad industry support. According to the organization, it is a set of open specifications to integrate apps with portals, EHRs, health information exchanges, and other health IT systems.

The other one is the HAPI FHIR. It is a new library for adding FHIR messaging to applications. Fundamentally, it was developed at the University Health Network in Ontario, Canada. Moreover, this is open source as well as free to use.

How FHIR Works?

The FHIR frameworks are built around the concept of resources basic units of interoperability and modular components that can be assembled into working systems to try to resolve clinical, administrative, and infrastructural problems in healthcare.

Moreover, for administrative concepts, FHIR offers software development tools and resources including providers, patients, organizations and devices, as well as a variety of clinical concepts such as medications,  problems, diagnostics, care plans, and financial issues, among others.

Furthermore, it is designed specifically for the web and offers resources and foundations based on JSON, XML, HTTP, Atom & OAuth structures. Besides, we can reuse tools to improve interoperability to retrieve the history of a specific resource or a specific version.

However, the specification is online, fully hyperlinked, and can be linked from the resource of a property to the data type of that property. One of the best features it attains is, we can use FHIR in mobile phone applications, EHR-based data sharing, cloud communications, and among institutional healthcare providers.

There are three parts of the FHIR specification, such as:

  1. General documentation
  2. Implementation
  3. Resource list

The general documentation describes how resources are defined and gives background material, including definitions of data types, codes, and XML & JSON formats. Moreover, using the RESTful architecture programming interface, users can use resources as clinical documents or in a service-based architecture.

There is a framework introduced by FHIR for extending and adapting resources. So, it can be read by any system, regardless of the way they were developed. By using the same framework as retrieving other resources, extension definitions can be retrieved. And, each resource carries human-readable text representation via HTML.

How is FHIR Different?

It's hardly surprising that the next generation standard is based on web technology for flexible, fast, and cost-effective development.

Here are some paradigms of interoperability, which FHIR supports:

  • RESTful web services
  • Documents
  • Messages
  • Services

We have some other standards as well that separately support these paradigms. Still, they require an interface to move from one to the other; whereas, FHIR has the same content in all four paradigms.

We can represent a clinical attribute like a blood pressure reading by using FHIR and use it unchanged in documents,  messages, RESTful approaches, as well as services.

What is the FHIR Resource?

In FHIR, the basic building block is a Resource.

In simple words, all exchangeable content in FHIR is defined as a resource. These resources have standard, agreed-upon atomic data elements which have regular interest over-sharing entities.

Resources have several sets of characteristics:

  • A standard way to define and be designed, developing them from data types that represent common reusable patterns of elements
  • The common set of metadata
  • The human-readable component

Resource types such as administrative, infrastructure, and clinical elements, are as follows:

  • Patient
  • List
  • Care Plan
  • Composition
  • Family History
  • Medication
  • Questionnaire
  • Organization
  • Media

What is an FHIR Profile?

A statement of the use of one or more FHIR Resources for a particular use case is what we call a Resource Profile.

There are three main parts of a Resource Profile:

  1. A Metadata Section: This represents the profile & supports registry searching.
  2. Structures: It determines and illustrates how a Resource or Data Type is used.
  3. Extension Definitions: It sets extensions which we further use in structures.

Moreover, an FHIR Profile may involve constraints on Resources as well as data types, especially, controlling how we use terminology in extension definitions.

Though, some common profiles will be included as part of future versions of the FHIR specification. Even, those profiles will also be made available on a public server to enable developers to access them. Besides, an FHIR Profile is considered analogous to an implementation guide for any specific use case.

Why is FHIR is an Emerging Healthcare Interoperability Standard?

  • Typically, it is a next-generation scalable standards framework. And, it is web services based as well as supported by current exchange infrastructure also.
  • It can construct/deconstruct CDA documents from various data sources and systems.
  • It is created by implementers for fast, flexible, and open application development, and also reduces cost and complexity.


An open, standards-based platform for medical apps is what we call SMART on FHIR. It is intended to lower the barriers to electronic health record systems to participate in an app ecosystem. 

It is built on two technology efforts. The first one is the Harvard-based SMART Platforms Project, and the other one is the HL7® Fast Health Information Resources (FHIR®). 

In February 2014 at HIMSS 14, an initial version of SMART on FHIR was demonstrated. Since then, industry associations have formed to leverage SMART on FHIR. 

Applications of FHIR

It is possible to consider FHIR for several applications:

  • FHIR offers the means to create RESTful APIs.
  • To allow easier external interfacing, Map existing internal interfaces to FHIR.
  • Connect systems with FHIR APIs, which are more easily created and more cost-effective than traditional HL7 V2 interfaces.
  • It addresses several new use cases, including web, mobile, and cloud.
  • Facilitate external decision support systems to independently access data stored in multiple end-user healthcare systems through APIs.

Is FHIR Being Used Today?

Here are some projects underway for the FHIR usage:

1. The Argonaut Project

It is a joint project between HL7 and several healthcare & vendor organizations. It strives to develop a first-generation API and Core Data Services specification to enable increased information sharing for electronic health records, documents, and other health information based on FHIR specification.

2. Chat for FHIR implementations

3. The Health Services Platform Consortium (HSPC)

It is a non-profit membership organization which is formed by a collaboration of healthcare organizations, software vendors, and academia focused on building an open platform based on FHIR to enable rapid development of healthcare applications.

Moreover, for developers, this platform provides tools, and for development, provides a sandbox.

Benefits of FHIR

There are many improvements FHIR offers to us:

  • A heavy focus on implementation; fast and easy to implement
  • Many implementation libraries, numerous examples available to kick-start development
  • Free specification with no restrictions
  • Evolutionary improvement path from HL7 Version 2 and CDA - standards can co-exist and leverage each other
  • The solid foundation in Web standards, such as XML, JSON, HTTP, Atom, OAuth, etc.
  • A seamless exchange of information using messages or documents and also support for RESTful architectures
  • Compact and efficiently understood specifications
  • For ease of use by developers, a human-readable wire format
  • Especially for correctness, a solid ontology-based analysis with a rigorous formal mapping.

Points to Remember about HL7 FHIR

  • FHIR is an acronym for Fast Healthcare Interoperable Resource.
  • It unites the best features of HL7 V2, HL7 V3, as well as CDA while leveraging the latest web service technologies.
  • FHIR’s idea is based on RESTful web services. It is in contrast to the majority of IHE profiles which are further based on SOAP web services. The basic HTTP operations are incorporated, including Create, Read, Update and Delete with RESTful web services.
  • It is based on modular components called “resources” that we combine to solve administrative & clinical problems practically. We can extend and adapt these resources to provide a more manageable solution to the healthcare demand for optionality and customization.
  • Moreover, in March 2012, the FHIR specification was transferred from Grahame Grieve, a creator & architect, to HL7 International and was made freely available. Grieve started work a year earlier in response to outcomes from the HL7 Fresh Look task force. 
  • It is still being developed by HL7, but the first Draft Standard for Trial Use (DSTU) is currently available.

Final Thoughts

Hence, we have seen how FHIR is the next-generation standard framework with best features of HL7’s other standards, including v2, v3, and CDA product lines. Also, we have seen how FHIR is beneficial, especially while leveraging the latest web standards and applying a tight focus on implementability.

Thus, at Covetus, we understand the transformational phase Healthcare industry is going through, and therefore, we help you to be on the top of every technology innovations, market changes, regulatory changes and offering expertise in a wide range of medical standards like HL7, FHIR, DICOM, CCD, ICD-9, ICD-10.

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